feat(admin): add security and activity management features

lib/server/ip.go

@@ -0,0 +1,89 @@
+package server
+
+import (
+	"net"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+func clientIP(ctx *gin.Context) string {
+	if ctx == nil || ctx.Request == nil {
+		return ""
+	}
+	remoteIP := remoteAddrIP(ctx.Request)
+
+	// Only trust forwarding headers when remote hop looks like local/internal proxy.
+	if isPrivateOrLoopback(remoteIP) {
+		for _, candidate := range headerIPs(ctx.Request.Header) {
+			if isPublicIP(candidate) {
+				return candidate
+			}
+		}
+		candidates := headerIPs(ctx.Request.Header)
+		if len(candidates) > 0 {
+			return candidates[0]
+		}
+	}
+	return remoteIP
+}
+
+func headerIPs(header http.Header) []string {
+	keys := []string{
+		"X-Forwarded-For",
+		"X-Real-Ip",
+		"CF-Connecting-IP",
+		"X-Envoy-External-Address",
+		"Fly-Client-IP",
+	}
+	out := make([]string, 0, 4)
+	seen := map[string]bool{}
+	for _, key := range keys {
+		raw := strings.TrimSpace(header.Get(key))
+		if raw == "" {
+			continue
+		}
+		for _, part := range strings.Split(raw, ",") {
+			ip := normalizeIP(strings.TrimSpace(part))
+			if ip == "" || seen[ip] {
+				continue
+			}
+			seen[ip] = true
+			out = append(out, ip)
+		}
+	}
+	return out
+}
+
+func remoteAddrIP(request *http.Request) string {
+	host, _, err := net.SplitHostPort(strings.TrimSpace(request.RemoteAddr))
+	if err != nil {
+		return normalizeIP(strings.TrimSpace(request.RemoteAddr))
+	}
+	return normalizeIP(host)
+}
+
+func normalizeIP(raw string) string {
+	ip := net.ParseIP(strings.TrimSpace(raw))
+	if ip == nil {
+		return ""
+	}
+	return ip.String()
+}
+
+func isPublicIP(value string) bool {
+	ip := net.ParseIP(value)
+	if ip == nil || !ip.IsGlobalUnicast() {
+		return false
+	}
+	return !isPrivateOrLoopback(value)
+}
+
+func isPrivateOrLoopback(value string) bool {
+	ip := net.ParseIP(value)
+	if ip == nil {
+		return true
+	}
+	return ip.IsLoopback() || ip.IsPrivate() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast()
+}